Is is possible for transplanted grafts to be rejected months or years after a successful HT? If so how often and to what extent does that happen?
For men, the hair on the back of the scalp is considered permanent. It may thin a bit with aging, but even old men in their 80s, 90s, 100s will have hair at the back of their heads. So if you harvest the hairs from this permanent area, the transplanted hairs will act like the hairs on the back of the head and will have the same life span. This concept is called “donor dominance”. This is why hair transplants work for men. For women, it may be different and there is a small risk the transplanted hairs may not be as permanent as men.
Theoretically it is not possible for successfully transplanted hairs to be “rejected” years or months after it has grown, but I have seen a handful of patients over the last 20 years who have had transplanted hairs fall out. This may be due to a diagnosed condition such as DUPA (diffuse unpatterned alopecia) or other esoteric medical conditions.